You need a few things before you start to configure your server, namely credentials.

The credentials are: a username, password, SNMP Read only community string, and SNMP Read Write community string that is configured on the devices you want to manage. If you have a TACACS+ or RADIUS installation I would configure an identity for your Ciscoworks installation to use and give it level 15 permissions. You will also want at least the IP address of your default gateway for the server, this is the easiest on to discover initially.

When you have that information you'll want to log into your Ciscoworks installation, go to CiscoWorks Assistant, expand out workflows and step through the Server Setup.

Note there will be a difference in the discovery step if you have applied the December updates due to the discovery engine being moved from Campus to Comon Services.